The invention relates to a telescopic linkage for household appliances for transmitting adjusting movements and adjusting forces in the longitudinal linkage direction and around this in the direction of rotation from one linkage end to the other.
The telescopic linkage serves for transmitting adjusting movements in the longitudinal linkage direction and around this in the direction of rotation from one linkage end to the other, and has two tubular and/or rod-like telescopic parts, referred herein as longitudinal telescopic bodies, which are inserted one inside the other in the longitudinal linkage direction.
A type of telescopic linkage is disclosed in European Patent Application EP 0 718 745 A2 and, in the document, the linkage connects the gas faucet of a gas cooking point to a manually actuable rotary knob (operating element) on the front of a gas cooker. By virtue of manually pushing in the rotary knob, the telescopic linkage can be displaced inwards and an ignition safety device can, thus, be activated. This opens an ignition-safety-device gas route of which the ignition flame keeps the ignition safety device in an unblocking position, in which the gas faucet can be rotated open and closed by way of the rotary knob. When the ignition-safety-device flame is extinguished, the ignition safety device passes into a blocking position, in which it shuts off the entire gas feed through the gas faucet, regardless of the rotary position of the rotary knob. By virtue of the telescopic linkage being rotated by way of the rotary knob, the gas faucet can be opened to a more or less pronounced extent to adjust the size of the gas cooking flames at the gas faucet. The gas-adjusting rotary range of the telescopic linkage, thus, also of the gas faucet, is limited to, for example, 210xc2x0 by stops on the gas faucet. To adapt the length of the telescopic linkage to different construction or tolerance-induced dimensions between the gas faucet and a switching unit of the rotary knob, the two longitudinal telescopic bodies, which are plugged one inside the other in the longitudinal direction, can be fixed relative to one another in the longitudinal direction by an adjusting screw that is screwed transversally to the outer longitudinal telescopic body and can be braced against the inner longitudinal telescopic body. They have to be capable of being connected fixedly to one another in the longitudinal direction for the transmission of the adjusting force for the ignition safety device. For the transmission of torques, the outer telescopic body has a cross-sectional cross-shaped opening in the longitudinal direction and the inner telescopic body has a cross-shaped cross-section that fits into the cross-shaped opening. If, following the assembly of the gas cooker, it turns out that the telescopic length does not coincide precisely with the dimensions between the switching unit of the gas faucet and the rotary knob, then high-outlay removal of parts of the gas cooker and renewed adjustment of the telescopic length are subsequently necessary, which can only be done by a service engineer or fitter.
A further disadvantage of prior art gas cookers is the absence of a safeguard against unauthorized or accidental actuation of the rotary knob, e.g., during cleaning of the household appliance. Such actuation is also associated with the risk of gas being able to pass out in the unburned state or, during ignition, possibly resulting in a fire, for example, in the case of unauthorized operation by a child. Measures for safeguarding against unauthorized or accidental operation that are of straightforward construction and are inexpensive and straightforward to operate are also desirable in the case of electric household appliances such as, for example, electric cookers, ovens, automatic dishwashers, washing machines, and laundry dryers.
It is accordingly an object of the invention to provide a telescopic linkage for household appliances that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that constructs the telescopic linkage such that it can subsequently be adjusted to different lengths from outside the household appliance in which it is installed without there being any need for access to the telescopic linkage by dismantling the household appliance. The invention also is intended to configure a telescopic linkage that, by straightforward operation, can be switched over between an active and an inactive state to safeguard against unauthorized or accidental use of the relevant household appliance.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a household appliance telescopic linkage including at least two longitudinal telescopic bodies including a first body and a second body each having a linkage end, the bodies defining a longitudinal linkage direction, the first body at least partially inserted inside the second body in the longitudinal linkage direction and rotatable in the second body at least in a rotation direction, the bodies transmitting adjusting movements and adjusting forces from the linkage end of the first body to the linkage end of the second body in the longitudinal linkage direction and around the longitudinal linkage direction in the rotation direction, the bodies displaceable relative to one another in the longitudinal linkage direction and arrestable with one another for joint longitudinal movement, the bodies rotatable relative to one another through an angle-of-rotation range about the longitudinal linkage axis between an axially arrested position in which the bodies are axially arrested with respect to one another and an axially released position in which the bodies are axially moveable with respect to one another, and due to the relative rotation, the bodies, at least in the axially arrested position, being additionally arrestable relative to one another in the rotation direction and releaseable from one another by rotation in a direction opposite the rotation direction.
The invention provides that the two longitudinal telescopic bodies can be rotated relative to one another, and an arresting mechanism can be actuated by rotation of the two longitudinal telescopic bodies relative to one another and releases the two longitudinal telescopic bodies in a first rotary-angle position, for displacement relative to one another in the longitudinal linkage direction, but connects the longitudinal telescopic bodies to one another such that they are longitudinally and rotationally fixed relative to one another, in a second rotary-angle position, for the transmission of the adjusting movements and of the adjusting forces in the longitudinal linkage direction and direction of rotation. The arresting mechanism has, for the rotationally fixed connection in the second rotary-angle position, an arresting device that at least initially counter a rotation of the two longitudinal telescopic bodies relative to one another from the second rotary-angle position in the direction of the first rotary-angle position by a resistance that can be overcome manually and is greater than the torque that can be transmitted by the telescopic linkage for the adjusting movements in a household appliance.
In accordance with a further feature of the invention, the bodies each have a coupling toothing formation with coupling teeth, the coupling teeth running transverse to the longitudinal linkage direction, and the coupling teeth of each of the bodies selectively engaged and disengaged with one another by rotation of the bodies.
In accordance with an added feature of the invention, there is provided an arresting mechanism connected to the bodies, a rotation of the bodies with respect to one another actuating the arresting mechanism, in a first rotary-angle position, to release the bodies for displacement relative to one another in the longitudinal linkage direction, and to longitudinally and rotationally fix the bodies relative to one another in a second rotary-angle position for transmission of the adjusting movements and of the adjusting forces in the longitudinal linkage direction and the rotation direction, the arresting mechanism having, for the rotationally fixed connection in the second rotary-angle position, an arresting device at least initially countering a rotation of the bodies relative to one another from the second rotary-angle position in a direction of the first rotary-angle position with a resistance to be manually overcome and greater than a torque to be transmitted by the telescopic linkage for the adjusting movements in the household appliance.
In accordance with an additional feature of the invention, the arresting mechanism has at least one blocking body, the blocking body is guided on the second body and moves transverse to the longitudinal linkage direction, the first body has a coupling toothing formation with coupling teeth having tooth gaps running transverse to the longitudinal linkage direction, the blocking body has a coupling toothing formation with coupling teeth having tooth gaps running transverse to the longitudinal linkage direction, the coupling toothing formation of the blocking body is disposed opposite the coupling toothing formation of the first body, the blocking body and the first body form a carry-along connection therebetween transferring torque movements of the first body to movements of the blocking body transverse to the longitudinal telescopic direction, and the carry-along connection engaging and disengaging the coupling toothing formation of the blocking body and the coupling toothing formation of the first body.
In accordance with yet another feature of the invention, there is provided at least one spring forcing the blocking body in a direction transverse to the longitudinal linkage direction towards the first body from a disengagement position of the coupling toothing formations into an engagement position of the coupling toothing formations.
In accordance with yet a further feature of the invention, the second body has a guide body, the blocking body is guided transverse to the longitudinal linkage direction on the guide body, the arresting mechanism has protrusions and cutouts, one of the protrusions and the cutouts is disposed on the blocking body and another of the protrusions and the cutouts is disposed on the guide body, one of the blocking body and the guide body having the cutouts has a sliding surface and the protrusions and the cutouts latch one inside another only in predetermined rotary-angle positions of the bodies, at least in the first rotary-angle position and the second rotary-angle position of the bodies, a manual twisting movement between the bodies is necessary for a subsequent unlatching operation of the bodies, and in an unlatched state of the bodies, the protrusions are braced against the sliding surface.
In accordance with yet an added feature of the invention, between the first rotary-angle position and the second rotary-angle position is an intermediate rotary-angle position, the coupling toothing formations are disengaged in the intermediate rotary-angle position, in the intermediate rotary-angle position, the bodies are displaceable relative to one another in the longitudinal linkage direction for a length adjustment of the telescopic linkage, a protrusion is disposed between the blocking body and the guide body, the protrusion projecting from one of the blocking body and the guide body to another of the blocking body and the guide body, and when the bodies are rotated between the second rotary-angle position, in which the bodies are connected to one another for joint longitudinal movement, and the intermediate rotary-angle position, the protrusion is freely moveable, runs onto a mating surface of the one of the blocking body and the guide body not having the protrusion with further rotary movement from the intermediate rotary-angle position in a direction of the first rotary-angle position, and produces a frictional resistance counteracting such rotary movement of the bodies.
In accordance with yet an additional feature of the invention, there is provided a slot having a slot edge is formed in the one of the blocking body and the guide body having the mating surface, the protrusion projecting into the slot over a movement path corresponding to a rotary angle between the second rotary-angle position and the intermediate rotary-angle position, and the protrusion running over the slot edge onto the mating surface when rotation occurs beyond the intermediate rotary position in a direction of the first rotary-angle position.
In accordance with again another feature of the invention, the protrusions have a given height, between the guide body and the blocking body is an interspace smaller than the height of the protrusions, and the protrusions are clamped in between the guide body and the blocking body during relative displacement of the guide body and the blocking body to one another when the bodies are rotated relative to one another.
In accordance with again a further feature of the invention, the blocking body is two blocking bodies disposed opposite one another on sides of the first body.
In accordance with again an added feature of the invention, the spring has a spring force sufficiently large enough to rotate, through the blocking body, the bodies relative to one another from the intermediate rotary-angle position into the second rotary-angle position.
In accordance with again an additional feature of the invention, the second rotary-angle position is a locking position.
In accordance with still another feature of the invention, the blocking body is two blocking bodies disposed on the first body and the spring is a spring clip encompassing the two blocking bodies and forcing the two blocking bodies toward one another in a direction of the first body.
In accordance with still a further feature of the invention, the spring and the protrusions each having a movement-blocking force sufficiently large in each case to withstand rotary torques between the bodies at least as large as torques for transmitting the adjusting movements and the adjusting forces of the telescopic linkage in the rotation direction.
With the objects of the invention in view, in a household appliance having a manual operating element and a functional part, there is also provided a telescopic linkage for connecting the manual operating element to the functional part, the telescopic linkage including at least two longitudinal telescopic bodies including a first body and a second body each having a linkage end, the bodies defining a longitudinal linkage direction, the first body at least partially inserted inside the second body in the longitudinal linkage direction and rotatable in the second body at least in a rotation direction, the bodies transmitting adjusting movements and adjusting forces from the linkage end of the first body to the linkage end of the second body in the longitudinal linkage direction and around the longitudinal linkage direction in the rotation direction, the bodies displaceable relative to one another in the longitudinal linkage direction and arrestable with one another for joint longitudinal movement, the bodies rotatable relative to one another through an angle-of-rotation range about the longitudinal linkage axis between an axially arrested position in which the bodies are axially arrested with respect to one another and an axially released position in which the bodies are axially moveable with respect to one another, and due to the relative rotation, the bodies, at least in the axially arrested position, being additionally arrestable relative to one another in the rotation direction and releaseable from one another by rotation in a direction opposite the rotation direction.
The invention has the advantage, on one hand, that the telescopic linkage, by a manual actuating element at one end, can be displaced in the longitudinal linkage direction and can be rotated around the longitudinal linkage direction, and can transmit axial forces and torque in the process, but, on the other hand, by the operating element, the two longitudinal telescopic bodies can be rotated relative to one another and can then be displaced relative to one another in the longitudinal telescopic direction for the adjustment of different telescopic lengths. The configuration also gives a safeguard against unauthorized (child proofing) or accidental switching on of the household appliance, for example, during cleaning of the front of the household appliance.
In accordance with a concomitant feature of the invention, the appliance has a cooking point with a gas faucet, an ignition safety device, and the telescopic linkage actuates the ignition safety device through the operating element in the longitudinal linkage direction and in the rotation direction.
Other features that are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a telescopic linkage for household appliances, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following by description of specific embodiments when read in connection with the accompanying drawings.